diff options
Diffstat (limited to 'src/mongo/db/dbhelpers.h')
| -rw-r--r-- | src/mongo/db/dbhelpers.h | 352 |
1 files changed, 177 insertions, 175 deletions
diff --git a/src/mongo/db/dbhelpers.h b/src/mongo/db/dbhelpers.h index a0ca0f0bc3d..146943fcfc3 100644 --- a/src/mongo/db/dbhelpers.h +++ b/src/mongo/db/dbhelpers.h @@ -35,194 +35,196 @@ namespace mongo { - class Collection; - class Cursor; - class OperationContext; - struct KeyRange; - struct WriteConcernOptions; +class Collection; +class Cursor; +class OperationContext; +struct KeyRange; +struct WriteConcernOptions; + +/** + * db helpers are helper functions and classes that let us easily manipulate the local + * database instance in-proc. + * + * all helpers assume locking is handled above them + */ +struct Helpers { + class RemoveSaver; + + /* ensure the specified index exists. + + @param keyPattern key pattern, e.g., { ts : 1 } + @param name index name, e.g., "name_1" + + This method can be a little (not much) cpu-slow, so you may wish to use + OCCASIONALLY ensureIndex(...); + + Note: does nothing if collection does not yet exist. + */ + static void ensureIndex(OperationContext* txn, + Collection* collection, + BSONObj keyPattern, + bool unique, + const char* name); + + /* fetch a single object from collection ns that matches query. + set your db SavedContext first. + + @param query - the query to perform. note this is the low level portion of query so "orderby : ..." + won't work. + + @param requireIndex if true, assert if no index for the query. a way to guard against + writing a slow query. + + @return true if object found + */ + static bool findOne(OperationContext* txn, + Collection* collection, + const BSONObj& query, + BSONObj& result, + bool requireIndex = false); + + static RecordId findOne(OperationContext* txn, + Collection* collection, + const BSONObj& query, + bool requireIndex); /** - * db helpers are helper functions and classes that let us easily manipulate the local - * database instance in-proc. + * @param foundIndex if passed in will be set to 1 if ns and index found + * @return true if object found + */ + static bool findById(OperationContext* txn, + Database* db, + const char* ns, + BSONObj query, + BSONObj& result, + bool* nsFound = 0, + bool* indexFound = 0); + + /* TODO: should this move into Collection? + * uasserts if no _id index. + * @return null loc if not found */ + static RecordId findById(OperationContext* txn, Collection* collection, const BSONObj& query); + + /** + * Get the first object generated from a forward natural-order scan on "ns". Callers do not + * have to lock "ns". + * + * Returns true if there is such an object. An owned copy of the object is placed into the + * out-argument "result". * - * all helpers assume locking is handled above them + * Returns false if there is no such object. + */ + static bool getSingleton(OperationContext* txn, const char* ns, BSONObj& result); + + /** + * Same as getSingleton, but with a reverse natural-order scan on "ns". */ - struct Helpers { + static bool getLast(OperationContext* txn, const char* ns, BSONObj& result); - class RemoveSaver; + /** + * Performs an upsert of "obj" into the collection "ns", with an empty update predicate. + * Callers must have "ns" locked. + */ + static void putSingleton(OperationContext* txn, const char* ns, BSONObj obj); + + /** + * you have to lock + * you do not have to have Context set + * o has to have an _id field or will assert + */ + static void upsert(OperationContext* txn, + const std::string& ns, + const BSONObj& o, + bool fromMigrate = false); + + // TODO: this should be somewhere else probably + /* Takes object o, and returns a new object with the + * same field elements but the names stripped out. + * Example: + * o = {a : 5 , b : 6} --> {"" : 5, "" : 6} + */ + static BSONObj toKeyFormat(const BSONObj& o); - /* ensure the specified index exists. + /* Takes object o, and infers an ascending keyPattern with the same fields as o + * Example: + * o = {a : 5 , b : 6} --> {a : 1 , b : 1 } + */ + static BSONObj inferKeyPattern(const BSONObj& o); + + /** + * Takes a namespace range, specified by a min and max and qualified by an index pattern, + * and removes all the documents in that range found by iterating + * over the given index. Caller is responsible for insuring that min/max are + * compatible with the given keyPattern (e.g min={a:100} is compatible with + * keyPattern={a:1,b:1} since it can be extended to {a:100,b:minKey}, but + * min={b:100} is not compatible). + * + * Caller must hold a write lock on 'ns' + * + * Returns -1 when no usable index exists + * + * Does oplog the individual document deletions. + * // TODO: Refactor this mechanism, it is growing too large + */ + static long long removeRange(OperationContext* txn, + const KeyRange& range, + bool maxInclusive, + const WriteConcernOptions& secondaryThrottle, + RemoveSaver* callback = NULL, + bool fromMigrate = false, + bool onlyRemoveOrphanedDocs = false); - @param keyPattern key pattern, e.g., { ts : 1 } - @param name index name, e.g., "name_1" - This method can be a little (not much) cpu-slow, so you may wish to use - OCCASIONALLY ensureIndex(...); + // TODO: This will supersede Chunk::MaxObjectsPerChunk + static const long long kMaxDocsPerChunk; - Note: does nothing if collection does not yet exist. - */ - static void ensureIndex(OperationContext* txn, - Collection* collection, - BSONObj keyPattern, - bool unique, - const char *name); + /** + * Get sorted disklocs that belong to a range of a namespace defined over an index + * key pattern (KeyRange). + * + * @param chunk range of a namespace over an index key pattern. + * @param maxChunkSizeBytes max number of bytes that we will retrieve locs for, if the + * range is estimated larger (from avg doc stats) we will stop recording locs. + * @param locs set to record locs in + * @param estChunkSizeBytes chunk size estimated from doc count and avg doc size + * @param chunkTooBig whether the chunk was estimated larger than our maxChunkSizeBytes + * @param errmsg filled with textual description of error if this call return false + * + * @return NamespaceNotFound if the namespace doesn't exist + * @return IndexNotFound if the index pattern doesn't match any indexes + * @return InvalidLength if the estimated size exceeds maxChunkSizeBytes + */ + static Status getLocsInRange(OperationContext* txn, + const KeyRange& range, + long long maxChunkSizeBytes, + std::set<RecordId>* locs, + long long* numDocs, + long long* estChunkSizeBytes); - /* fetch a single object from collection ns that matches query. - set your db SavedContext first. + /** + * Remove all documents from a collection. + * You do not need to set the database before calling. + * Does not oplog the operation. + */ + static void emptyCollection(OperationContext* txn, const char* ns); - @param query - the query to perform. note this is the low level portion of query so "orderby : ..." - won't work. + /** + * for saving deleted bson objects to a flat file + */ + class RemoveSaver { + MONGO_DISALLOW_COPYING(RemoveSaver); - @param requireIndex if true, assert if no index for the query. a way to guard against - writing a slow query. + public: + RemoveSaver(const std::string& type, const std::string& ns, const std::string& why); + ~RemoveSaver(); - @return true if object found - */ - static bool findOne(OperationContext* txn, - Collection* collection, - const BSONObj &query, - BSONObj& result, - bool requireIndex = false); - - static RecordId findOne(OperationContext* txn, - Collection* collection, - const BSONObj &query, - bool requireIndex); - - /** - * @param foundIndex if passed in will be set to 1 if ns and index found - * @return true if object found - */ - static bool findById(OperationContext* txn, - Database* db, const char *ns, BSONObj query, BSONObj& result, - bool* nsFound = 0, bool* indexFound = 0 ); - - /* TODO: should this move into Collection? - * uasserts if no _id index. - * @return null loc if not found */ - static RecordId findById(OperationContext* txn, - Collection* collection, const BSONObj& query); - - /** - * Get the first object generated from a forward natural-order scan on "ns". Callers do not - * have to lock "ns". - * - * Returns true if there is such an object. An owned copy of the object is placed into the - * out-argument "result". - * - * Returns false if there is no such object. - */ - static bool getSingleton(OperationContext* txn, const char *ns, BSONObj& result); - - /** - * Same as getSingleton, but with a reverse natural-order scan on "ns". - */ - static bool getLast(OperationContext* txn, const char *ns, BSONObj& result); - - /** - * Performs an upsert of "obj" into the collection "ns", with an empty update predicate. - * Callers must have "ns" locked. - */ - static void putSingleton(OperationContext* txn, const char *ns, BSONObj obj); - - /** - * you have to lock - * you do not have to have Context set - * o has to have an _id field or will assert - */ - static void upsert( OperationContext* txn, - const std::string& ns, - const BSONObj& o, - bool fromMigrate = false ); - - // TODO: this should be somewhere else probably - /* Takes object o, and returns a new object with the - * same field elements but the names stripped out. - * Example: - * o = {a : 5 , b : 6} --> {"" : 5, "" : 6} - */ - static BSONObj toKeyFormat( const BSONObj& o ); - - /* Takes object o, and infers an ascending keyPattern with the same fields as o - * Example: - * o = {a : 5 , b : 6} --> {a : 1 , b : 1 } - */ - static BSONObj inferKeyPattern( const BSONObj& o ); - - /** - * Takes a namespace range, specified by a min and max and qualified by an index pattern, - * and removes all the documents in that range found by iterating - * over the given index. Caller is responsible for insuring that min/max are - * compatible with the given keyPattern (e.g min={a:100} is compatible with - * keyPattern={a:1,b:1} since it can be extended to {a:100,b:minKey}, but - * min={b:100} is not compatible). - * - * Caller must hold a write lock on 'ns' - * - * Returns -1 when no usable index exists - * - * Does oplog the individual document deletions. - * // TODO: Refactor this mechanism, it is growing too large - */ - static long long removeRange( OperationContext* txn, - const KeyRange& range, - bool maxInclusive, - const WriteConcernOptions& secondaryThrottle, - RemoveSaver* callback = NULL, - bool fromMigrate = false, - bool onlyRemoveOrphanedDocs = false ); - - - // TODO: This will supersede Chunk::MaxObjectsPerChunk - static const long long kMaxDocsPerChunk; - - /** - * Get sorted disklocs that belong to a range of a namespace defined over an index - * key pattern (KeyRange). - * - * @param chunk range of a namespace over an index key pattern. - * @param maxChunkSizeBytes max number of bytes that we will retrieve locs for, if the - * range is estimated larger (from avg doc stats) we will stop recording locs. - * @param locs set to record locs in - * @param estChunkSizeBytes chunk size estimated from doc count and avg doc size - * @param chunkTooBig whether the chunk was estimated larger than our maxChunkSizeBytes - * @param errmsg filled with textual description of error if this call return false - * - * @return NamespaceNotFound if the namespace doesn't exist - * @return IndexNotFound if the index pattern doesn't match any indexes - * @return InvalidLength if the estimated size exceeds maxChunkSizeBytes - */ - static Status getLocsInRange( OperationContext* txn, - const KeyRange& range, - long long maxChunkSizeBytes, - std::set<RecordId>* locs, - long long* numDocs, - long long* estChunkSizeBytes ); - - /** - * Remove all documents from a collection. - * You do not need to set the database before calling. - * Does not oplog the operation. - */ - static void emptyCollection(OperationContext* txn, const char *ns); - - /** - * for saving deleted bson objects to a flat file - */ - class RemoveSaver { - MONGO_DISALLOW_COPYING(RemoveSaver); - public: - RemoveSaver(const std::string& type, const std::string& ns, const std::string& why); - ~RemoveSaver(); - - void goingToDelete( const BSONObj& o ); - - private: - boost::filesystem::path _root; - boost::filesystem::path _file; - std::ofstream* _out; - }; + void goingToDelete(const BSONObj& o); + private: + boost::filesystem::path _root; + boost::filesystem::path _file; + std::ofstream* _out; }; +}; -} // namespace mongo +} // namespace mongo |